This invention relates generally to sanitation systems for mobile homes and in particular to an improved vent structure for the flush water holding tank in such a system to allow air to pass into and out of the tank while preventing water from escaping through the vent structure.
The above referenced patent applications disclose a cassette type sanitary system particularly adapted to be mounted within the interior compartment of a mobile recreational vehicle (RV). Wastes generated during use of the sanitary system are deposited in a holding tank which can be conveniently removed from the RV through an exterior access door where it can be transported to a disposal site and emptied.
This application is particularly directed to an improved vent structure for the flush water holding tank to provide for a flow of air to the tank to replace water removed for toilet bowl flushing purposes and to provide resistance to water leakage from the tank when the RV is moving or parked on an incline. Briefly, the vent structure includes a cylindrical boss extending through the top wall of the tank and having an axial bore therethrough. The boss is located in a well formed at a high point in the top wall and the well is covered by a cap. The cap is in turn integrally connected to an actuating shaft that is operable to open and close the waste inlet valve for the waste holding tank.
A float member including a buoyant body is mounted for reciprocation within the boss, one end of the float member extending above the boss and the other end receiving the buoyant body and extending into the tank and a seal arrangement for closing off the flow of vent air when the float member is buoyed upwardly by the buoyant body as a result of the flush water changing its position in the tank such as from being parked on an incline or being bounced by movement of the RV. A flow path for vent air is defined through the tank and the bore to equalize the interior pressure of the tank with the exterior pressure. Upward movement of the float member seals the bore and prevents water from escaping through the boss around the top wall.
A benefit of such a vent structure is that functions of flush and venting are conveniently positioned at one location thereby combining functions and reducing parts to be installed or stocked for repair, saving time in construction, and providing a product the surfaces of which are substantially unobstructed by additional ports and sealing caps so as to be easy to maintain and clean, be appealing and present the interior of the RV with an efficient product.
Other benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings.